C# 实现WindowsHook 类

 

  1using System;
  2using System.Runtime.InteropServices;
  3using System.Reflection;
  4using System.Threading;
  5
  6using System.Windows.Forms;
  7
  8
  9namespace GlobalHookDemo  {
 10    
 11    /**//// <summary>
 12    /// This class allows you to tap keyboard and mouse and / or to detect their activity even when an 
 13    /// application runes in background or does not have any user interface at all. This class raises 
 14    /// common .NET events with KeyEventArgs and MouseEventArgs so you can easily retrive any information you need.
 15    /// </summary>
 16    /// <remarks>
 17    ///     created by - Georgi
 18    ///     created on - 22.05.2004 13:08:01
 19    /// </remarks>
 20    public class UserActivityHook : object {
 21        
 22        /**//// <summary>
 23        /// Default constructor - starts hooks automatically
 24        /// </summary>
 25        public UserActivityHook() {
 26            Start();
 27        }
 28        
 29        ~UserActivityHook() { 
 30            Stop();
 31        } 
 32
 33        public event MouseEventHandler OnMouseActivity;
 34        public event KeyEventHandler KeyDown;
 35        public event KeyPressEventHandler KeyPress;
 36        public event KeyEventHandler KeyUp;
 37
 38        public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
 39
 40        static int hMouseHook = 0; //Declare mouse hook handle as int.
 41        static int hKeyboardHook = 0; //Declare keyboard hook handle as int.
 42
 43        //values from Winuser.h in Microsoft SDK.
 44        public const int WH_MOUSE_LL     = 14;    //mouse hook constant
 45        public const int WH_KEYBOARD_LL = 13;    //keyboard hook constant    
 46
 47        HookProc MouseHookProcedure; //Declare MouseHookProcedure as HookProc type.
 48        HookProc KeyboardHookProcedure; //Declare KeyboardHookProcedure as HookProc type.
 49            
 50
 51        //Declare wrapper managed POINT class.
 52        [StructLayout(LayoutKind.Sequential)]
 53        public class POINT 
 54        {
 55            public int x;
 56            public int y;
 57        }
 58
 59        //Declare wrapper managed MouseHookStruct class.
 60        [StructLayout(LayoutKind.Sequential)]
 61        public class MouseHookStruct 
 62        {
 63            public POINT pt;
 64            public int hwnd;
 65            public int wHitTestCode;
 66            public int dwExtraInfo;
 67        }
 68
 69        //Declare wrapper managed KeyboardHookStruct class.
 70        [StructLayout(LayoutKind.Sequential)]
 71        public class KeyboardHookStruct
 72        {
 73            public int vkCode;    //Specifies a virtual-key code. The code must be a value in the range 1 to 254. 
 74            public int scanCode; // Specifies a hardware scan code for the key. 
 75            public int flags;  // Specifies the extended-key flag, event-injected flag, context code, and transition-state flag.
 76            public int time; // Specifies the time stamp for this message.
 77            public int dwExtraInfo; // Specifies extra information associated with the message. 
 78        }
 79
 80
 81        //Import for SetWindowsHookEx function.
 82        //Use this function to install a hook.
 83        [DllImport("user32.dll",CharSet=CharSet.Auto,
 84            CallingConvention=CallingConvention.StdCall)]
 85        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, 
 86            IntPtr hInstance, int threadId);
 87
 88        //Import for UnhookWindowsHookEx.
 89        //Call this function to uninstall the hook.
 90        [DllImport("user32.dll",CharSet=CharSet.Auto,
 91             CallingConvention=CallingConvention.StdCall)]
 92        public static extern bool UnhookWindowsHookEx(int idHook);
 93        
 94        //Import for CallNextHookEx.
 95        //Use this function to pass the hook information to next hook procedure in chain.
 96        [DllImport("user32.dll",CharSet=CharSet.Auto,
 97             CallingConvention=CallingConvention.StdCall)]
 98        public static extern int CallNextHookEx(int idHook, int nCode, 
 99            Int32 wParam, IntPtr lParam);  
100
101        public void Start()
102        {
103            // install Mouse hook 
104            if(hMouseHook == 0)
105            {
106                // Create an instance of HookProc.
107                MouseHookProcedure = new HookProc(MouseHookProc);
108
109                hMouseHook = SetWindowsHookEx( WH_MOUSE_LL,
110                    MouseHookProcedure, 
111                    Marshal.GetHINSTANCE(
112                        Assembly.GetExecutingAssembly().GetModules()[0]),
113                    0);
114
115                //If SetWindowsHookEx fails.
116                if(hMouseHook == 0 )    {
117                    Stop();
118                    throw new Exception("SetWindowsHookEx failed.");
119                }
120            }
121            
122            // install Keyboard hook 
123            if(hKeyboardHook == 0)
124            {
125                KeyboardHookProcedure = new HookProc(KeyboardHookProc);
126                hKeyboardHook = SetWindowsHookEx( WH_KEYBOARD_LL,
127                    KeyboardHookProcedure, 
128                    Marshal.GetHINSTANCE(
129                    Assembly.GetExecutingAssembly().GetModules()[0]),
130                    0);
131
132                //If SetWindowsHookEx fails.
133                if(hKeyboardHook == 0 )    {
134                    Stop();
135                    throw new Exception("SetWindowsHookEx ist failed.");
136                }
137            }
138        }
139
140        public void Stop()
141        {
142            bool retMouse =true;
143            bool retKeyboard = true;
144            if(hMouseHook != 0)
145            {
146                retMouse = UnhookWindowsHookEx(hMouseHook);
147                hMouseHook = 0;
148            } 
149            
150            if(hKeyboardHook != 0)
151            {
152                retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
153                hKeyboardHook = 0;
154            } 
155            
156            //If UnhookWindowsHookEx fails.
157            if (!(retMouse && retKeyboard)) throw new Exception("UnhookWindowsHookEx failed.");
158        }
159
160
161
162          private const int WM_MOUSEMOVE = 0x200;
163          private const int WM_LBUTTONDOWN = 0x201;
164          private const int WM_RBUTTONDOWN = 0x204;
165          private const int WM_MBUTTONDOWN = 0x207;
166          private const int WM_LBUTTONUP = 0x202;
167          private const int WM_RBUTTONUP = 0x205;
168          private const int WM_MBUTTONUP = 0x208;
169          private const int WM_LBUTTONDBLCLK = 0x203;
170          private const int WM_RBUTTONDBLCLK = 0x206;
171        private const int WM_MBUTTONDBLCLK = 0x209;
172
173        private int MouseHookProc(int nCode, Int32 wParam, IntPtr lParam)
174        {
175            // if ok and someone listens to our events
176            if ((nCode >= 0) && (OnMouseActivity!=null)) {
177                
178                MouseButtons button=MouseButtons.None;
179                switch (wParam)
180                {
181                    case WM_LBUTTONDOWN: 
182                    //case WM_LBUTTONUP: 
183                    //case WM_LBUTTONDBLCLK: 
184                        button=MouseButtons.Left; 
185                        break;
186                    case WM_RBUTTONDOWN: 
187                    //case WM_RBUTTONUP: 
188                    //case WM_RBUTTONDBLCLK: 
189                        button=MouseButtons.Right; 
190                        break;
191                    case WM_MBUTTONDOWN:
192                        button=MouseButtons.Middle;
193                        break;
194                }
195                int clickCount=0;
196                if (button!=MouseButtons.None)
197                    if (wParam==WM_LBUTTONDBLCLK || wParam==WM_RBUTTONDBLCLK) clickCount=2;
198                    else clickCount=1;
199                
200                //Marshall the data from callback.
201                MouseHookStruct MyMouseHookStruct = (MouseHookStruct) Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));
202                MouseEventArgs e=new MouseEventArgs(
203                                                    button, 
204                                                    clickCount, 
205                                                    MyMouseHookStruct.pt.x, 
206                                                    MyMouseHookStruct.pt.y, 
207                                                    0 );
208                OnMouseActivity(this, e);
209            }
210            return CallNextHookEx(hMouseHook, nCode, wParam, lParam); 
211        }
212
213
214        //The ToAscii function translates the specified virtual-key code and keyboard state to the corresponding character or characters. The function translates the code using the input language and physical keyboard layout identified by the keyboard layout handle.
215        [DllImport("user32")] 
216        public static extern int ToAscii(int uVirtKey, //[in] Specifies the virtual-key code to be translated. 
217                                         int uScanCode, // [in] Specifies the hardware scan code of the key to be translated. The high-order bit of this value is set if the key is up (not pressed). 
218                                         byte[] lpbKeyState, // [in] Pointer to a 256-byte array that contains the current keyboard state. Each element (byte) in the array contains the state of one key. If the high-order bit of a byte is set, the key is down (pressed). The low bit, if set, indicates that the key is toggled on. In this function, only the toggle bit of the CAPS LOCK key is relevant. The toggle state of the NUM LOCK and SCROLL LOCK keys is ignored.
219                                         byte[] lpwTransKey, // [out] Pointer to the buffer that receives the translated character or characters. 
220                                         int fuState); // [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise. 
221
222        //The GetKeyboardState function copies the status of the 256 virtual keys to the specified buffer. 
223        [DllImport("user32")] 
224        public static extern int GetKeyboardState(byte[] pbKeyState);
225
226        private const int WM_KEYDOWN         = 0x100;
227        private const int WM_KEYUP             = 0x101;
228        private const int WM_SYSKEYDOWN     = 0x104;
229        private const int WM_SYSKEYUP         = 0x105;
230
231        private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
232        {
233            // it was ok and someone listens to events
234            if ((nCode >= 0) && (KeyDown!=null || KeyUp!=null || KeyPress!=null))
235            {
236                KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct) Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
237                // raise KeyDown
238                if ( KeyDown!=null && ( wParam ==WM_KEYDOWN || wParam==WM_SYSKEYDOWN ))
239                {
240                    Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
241                    KeyEventArgs e = new KeyEventArgs(keyData);
242                    KeyDown(this, e);
243                }
244                
245                // raise KeyPress
246                if ( KeyPress!=null &&  wParam ==WM_KEYDOWN )
247                {
248                    byte[] keyState = new byte[256];
249                    GetKeyboardState(keyState);
250
251                    byte[] inBuffer= new byte[2];
252                    if (ToAscii(MyKeyboardHookStruct.vkCode,
253                            MyKeyboardHookStruct.scanCode,
254                            keyState,
255                            inBuffer,
256                            MyKeyboardHookStruct.flags)==1) 
257                            {
258                                KeyPressEventArgs e = new KeyPressEventArgs((char)inBuffer[0]);
259                                KeyPress(this, e);
260                            }
261                }
262                
263                // raise KeyUp
264                if ( KeyUp!=null && ( wParam ==WM_KEYUP || wParam==WM_SYSKEYUP ))
265                {
266                    Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
267                    KeyEventArgs e = new KeyEventArgs(keyData);
268                    KeyUp(this, e);
269                }
270
271            }
272            return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam); 
273        }
274    }
275}
276